Sunday, August 10, 2008

Weights and MeasuresMy lifelong incomprehension of imperial weights and measures can be told through two stories. The first concerns a memory of my father taking me and my twin brother for a walk in Savernake Forest when we were about twelve years old. In the forest my father got chatting to a local man. I have a memory of him being a blacksmith but I would not vouch for that (he seemed like a character out of a Thomas Hardy novel). The conversation turned to weights and measures. I remember this man pontificating to my father with passion about the short-sighted stupidity of the government for introducing the metric system and getting rid of the imperial system. Unfortunately, being only 12 years old at the time, I could not remember what was said in this argument, only the passionate way it was being expressed.

The second story concerns the teaching of weights and measures. I was born in the UK in 1965 and the metric system was introduced in 1971. Thus, the teachers at my primary school were grappling with the new system at the same time as my foundational knowledge of it was being taught. Suffice to say, I think my initial understanding of metric was grasped with a certain amount of politically-tinged mutterings. However, the metric system made sense to me: 100 centimetres to a metre; 100 metres to a kilometre—even though I had no real conception of what these lengths looked like, the system itself was easy to grasp. On the other hand the imperial system was just plain baffling—12 inches to a foot; three feet to a yard; god knows how many feet to a mile! And weights were different again: 16 ounces to the pound; 14 pounds to a stone—where was the logic in that? My problem was that I had assumed that imperial measurements belonged to a system but try as I might, I could not work out any rational principles underpinning it. So when it came to choosing between one and the other I really could not understand why people would prefer what to me was a wholly arcane, senseless system.

Very recently these two stories came together in an unexpected way. I was playing Trivial Pursuit with my family. A question came up about imperial weights and measures and mentioned the story of the blacksmith and wondered again what he could have said. My mother-in-law (who lives with us) was obviously listening, because the next few day she showed me a newspaper cutting. In all the English-speaking countries, land is traditionally measured by the acre, a very old Saxon unit that meant "field" as a unit an acre was originally a field of a size that a farmer could plough in a single day. The acre was never visualized as a square, it is long and narrow: one furlong by 4 rods. A furlong was the length that could be ploughed before the horses needed to be rested which worked out at 40 rods (presumably a rod is something to do with the length of the wood of the plough). The distance the constitutes the 'width' of a field also measured out in chains - 1 chain is the distance a team of horses could go back and forth before their harnesses (the ‘chain’) were taken off and the animals rested for the day. This amounted to four furlongs: four furrows in the ground measuring 4 rods in width.

I realised this article contained the substance of what that blacksmith had said to my father all those years before. Imperial measurements were traditional measuring systems marked out distances that measures the earth using parts of the human body or the distance over time taken for human or animal labour. These were concrete things that came out of experience rather than abstractions that were imposed on it. In essence, the crucial distinction between imperial and metric was the level of abstraction contained in each. The units of the imperial system were a mini picture of what the culture was like at the time of their inception. By contrast the metric system was based on a metal bar in a vault in Paris: some arbitrary length whose function was merely to create a standard around which a system of scientific measurement could be built. However, the problems came when anyone tried to combine the concrete things that made up the imperial system. (By the way, I assume it is called 'imperial' because of the various acts of the British parliament which heroically attempted to standardize all the ad hoc measuring systems in the 16th and 17th century). For when the ploughing regime of Anglo Saxon fields was matched with a mile--the distance that Roman soldiers marched over a thousand paces-- it is no wonder that imperial measurements did not fit neatly together .

The revelation in this story is I had simply failed to see the paradigm shift involved. As a 12 year old I was already thoroughly embedded in the abstract mathematical paradigm of metric. And it made perfect sense to me to see a measurement system as self contained and logically consistent. I had unquestioningly assumed that the imperial system derived from the same paradigmatic assumptions and had followed a similarly deducible logic; but merely substituting different scales: feet and inches for metres and centimetres. This ignorance of mine actually betrays a wider cultural ignorance about the land and the issues surrounding working and living on it. I am a 'townie,' I grew up in an urban environment and therefore have no conception of ploughing fields or horses, or any kind of agricultural labour. Distance to me is the distance that grids a map. Distance wasn’t real like something you could touch. I thought my misunderstanding of imperial measure was simply a question of units when it was actually a question of how one saw the world. No wonder the blacksmith's speech seemed so mysteriously compelling.

On a more academic note, the theme of being disconnected from the concrete signs of material existence in a world of abstraction (and absurdity) plays into a very modernist narrative of alienation. I wonder, is this the real reason behind the general but poorly-argued hostility to metric? Maybe? But I don't want to use this post as a forum to rehash such arguments. I should already be apparent that I am not one of the traditionalists who want to preserve metric; and if its preservation is metonymically linked to the preservation of the past, then the past can can wither and decay as far as I am concerned. But while I don't care for imperial measures politically, I do care for them as one cares for archeology or etymology. Like old buildings or the origins or words, the stories behind weights and measures are fascinating, because they are embedded with whole cultural history of experiences, like tiny time capsules. But, that said, campaigning to bring them back now as viable alternatives to what we have today is as anachronistic as trying to revive Anglo Saxon English or the steam train.

The inch represents the width of a thumb; in fact, in many languages, the word for "inch" is also the word for "thumb."

The foot (12 inches) was originally the length of a human foot, although it has evolved to be longer

The yard (3 feet) seems to have gotten its start in England as the name of a 3-foot measuring stick, but it is also understood to be the distance from the tip of the nose to the end of the middle finger of the outstretched hand. Henry I appears to have ordered construction of 3-foot standards, which were called "yards," and William of Malmsebury wrote that the yard was "the measure of his [the king's] own arm.” In fact, both the foot and the yard were established on the basis of the Saxon ynce, the foot being 36 barleycorns and the yard 108.

The fathom - if you stretch your arms out to the sides as far as possible, your total "arm span," from one fingertip to the other, is a fathom (6 feet).

Longer distances have more idiosyncratic origins..

The mile is a Roman unit, originally defined to be the length of 1000 paces of a Roman legion. A "pace" here means two steps, right and left, or about 5 feet, so the mile is a unit of roughly 5000 feet (For a long time no one felt any need to be precise about this, because distances longer than a furlong did not need to be measured exactly).

Weights

In traditional English law the various pound weights are related by stating all of them as multiples of the grain, which was originally the weight of a single barleycorn. Thus barleycorns are at the origin of both weight and distance units in the English system.

Gallons are always divided into 4 quarts, which are further divided into 2 pints each. For larger volumes of dry commodities, there are 2 gallons in a peck and 4 pecks in a bushel. Larger volumes of liquids were carried in barrels, hogsheads, or other containers whose size in gallons tended to vary with the commodity.

On both sides of the Atlantic, smaller volumes of liquid are traditionally measured in fluid ounces, which are at least roughly equal to the volume of one ounce of water. To accomplish this in the different systems, the smaller U.S. pint is divided into 16 fluid ounces, and the larger British pint is divided into 20 fluid ounces.